49. Polyrhachis laboriosus ^HNS. Pl. IV. figs. 21,22. B.M.

Worker. Length 4 lines.-Black: the abdomen covered with fine, short, golden pubescence. The anterior margin of the clypeus rounded, and having a slight carina down the middle; the mandibles short, triangular, and armed with five acute, ferruginous teeth; the palpi dark fusco-ferruginous; the head is finely longitudinally rugose, and thinly covered with cinereous pubescence. Thorax armed in front with two long acute spines, above, slightly concave, with the lateral margins forming a sharp raised carina, the disk with a little golden pubescence, which is frequently obliterated, the sides with a thin cinereous pubescence. Abdomen subglobose, the node of the peduncle with two long, erect, hooked spines directed backwards.

Hab. Sierra Leone. (Coll. Rev. D. F. Morgan.)